Flying wind shape with no tail, canted inlets and no visible weapons minimizes the radar signature.
As pilots begin ground tests of the B-21 Raider, Northrop Grumman (NG) is refining the craft’s shape and inlets to increase the bomber’s ability to remain undetected. The “low observable” (LO) technology of the B-21 uses a flying wing shape that looks like a flying saucer from the front. There is no vertical tail, a sharp edge around the entire nose and jagged edges on the landing gear doors – all LO features. The plane shares some characteristics with the B-2 Spirit, yet it appears to be smaller, narrower, lighter and most importantly, cheaper than its predecessor.
The U.S. Air Force (USAF) effectively killed the B-2 program with Northrop Grumman after a perceived reduced need for deep strike bombers after the Cold War, buying only 21 B-2s from Northrop Grumman (at a cost of over $2 billion each) for an order of 132.
The pictures shared by the U.S. Air Force (USAF) are from test flights. As expected, they show no add-ons such as weapon pylons that would increase the B-21’s radar signature. At this stage, the B-21 lacks special coatings; NG may apply these as ground tests continue. The B-21 is painted a light gray, which should minimize how visible it is to the naked eye and to infrared detection tools.
It is not clear from the photos whether the B-21 has two or four engines. The craft’s teardrop-shaped engine inlets blend into the wing’s surface, no doubt an aerodynamic concession to achieving the least radar cross section (RCS). Engine inlets appear big on radar and having them on top of the aircraft makes the inlets invisible to ground radar.
The B-21 is expected to have a high flight ceiling.
One of the more distinguishing features of the B-21 is its four-panel windscreen. This contains two large central panes and two arched, up-sloping rectangular side windows. The side windows are half the height of the central panes. Flat shapes at right angles will act to deflect radar waves, whereas a curved canopy would be detectable.
It is likely that the B-21 will have a refueling-related concealing mechanism like the B-2 Spirit’s rotating dorsal receptacle. The B-21 may need less frequent refueling than the B-2. The B-21 has a deeper, broader keel than the B-2, which suggests that it is able to carry more internal fuel than the B-2.
After the B-21’s design has been finalized, the USAF plans to incrementally add at least 100 B-21 Raiders to replace the B-1 Lancers and the B-2 Spirits currently in service. The B-21 is slated to complement, rather than replace, the B-52 Stratofortresses, currently being modernized with new Rolls Royce F130 engines and the replacement of 1960s radar technology with the Active Electronically Scanned Array system (AESA). AESA will heighten the B-52’s ability to target and navigate threat areas.